Fig. 6.

Changes in Notch1 and Numb during decidualization. A, To confirm Notch1 down-regulation during in vitro decidualization, we used two different decidualization-inducing treatments [cAMP or IL-1β along with E2 and MPA (E+P)]. HuF cells were immunoblotted for Notch1 and Notch1 target Notch4 and compared with controls. Both Notch1 and Notch4 were down-regulated as a consequence of the decidualization stimulus. B, Numb transcript levels are increased after 12 d of in vitro decidualization, whereas Notch1 gene expression levels were unchanged. C, Protein expression for Numb corroborated transcript levels and increased during decidualization, whereas Notch1 is down-regulated. These data point to a possible mechanism for posttranscriptional inhibition of Notch1 during decidualization and cellular differentiation. WB, Western blot.